Bed and platen printing machine with heated transfer ribbon



H. HARRISON April 1, 1969 BED AND PLATEN PRINTING MACHINE WITH HEATEDTRANSFER RIBBON Sheet Filed Jan. 20, 1967 I INVENTOR: HA RRY HARRISON H.HARRISON 3,435,760

BED AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON April 1,1969 Sheet Filed Jan. 20, 1967 Q 3 Q Q R HARRY HARRY ZW April 1, 1969 H.HARRISON 3,435,760

BED AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON Filed Jan.20', 1967 Sheet 3 of 3 INVENTOR;

HARRY HARRISON (Du/M d d n/lube,

United States Patent 3,435,760 BED; AND PLATEN PRINTING MACHINE WITHHEATED TRANSFER RIBBON Harry Harrison, Heywood, England, assignor toSulmist Limited, Heywood, Lancashire, England, a British company FiledJan. 20, 1967, Ser. No. 610,683 Claims priority, application GreatBritain, Mar. 4, 1966,

Int. Cl. B41f 1/00, 31/16; B44b /00 US. Cl. 101-287 3 Claims ABSTRACT OFTHE DISCLOSURE This invention relates to high speed cording machineswhich use heat transfer printing tape in the course of operation.

The technique in printing of using heat transfer printing tape is known.One type of tape used in this technique comprises a ribbon of cellophanecoated with size or ink which serves for printing of the charactersrequired. Such tape is hereinafter referred to as printing tape.

The technique may be used for printing a character such as anidentification number, a price, a quality, grade indication and thesemay be printed on lbags, wrappers, labels or other suitable articles. Inuse, the articles to be printed pass the coding machine one by one andreceive a suitable imprint.

In one known coding machine, a reciprocating, letterpress printingaction is used but this machine requires the conversion of rotary motioninto rectilinear motion.

It is the object of this invention to obviate or mitigate thisdisadvantage.

According to this invention there is provided a coding machine whichcomprises a printing head, adapted to carry a printing die and pastwhich the printing tape is adapted to pass in use, a printing tapeindexing means, solenoid means operatively connected to the printinghead and the indexing means, control means operatively connected to thesolenoid means and operable to energize the solenoid means and cause inturn a printing action of the head and then an indexing action of theindexing means.

Preferably, the solenoid means includes a printing solenoid to providethe printing action of the head and the movable core of which carriesthe printing head.

Also, the solenoid means further includes an indexing solenoid the coreof which when the solenoid is energized moves the indexing mechanismsuch as to index the tape past the printing head.

One embodiment of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings in which:

Patented Apr. 1, 1969 "ice FIG. 1 is a side elevation of the coder;

FIG. 2 is a plan of the coder; and

FIG. 3 is a circuit diagram of the control circuit.

Referring to FIGS. 1 and 2, the machine has a metal frame of invertedL-section and comprising a vertical side plate 2 and an upper horizontalplate 4. Depending from the lower edge of plate 2 are a pair of spacedlegs 5 on each of which is mounted a printing tape guide bar 6.Approximately at the mid height of the plate 2 there is a horizontalsolenoid bed 8 secured to the vertical plate 2 and overlying the tapeguides 6.

There is at one end of the side plate 2, level with the solenoid bed 8,a horizontal magazine spool axle and at the opposite end of the plate 2,a take-up spool axle 12, both axles projecting horizontally from thevertical side plate 2 and supporting a freely rotatable magazine spool.14 and a take-up spool 16 respectively. One or other of these spools14, 16 may be slightly spring loaded so as to give a slight tension tothe tape as it is being fed from one to the other. Heat transferprinting tape 18 on spool .14 is threaded under the guides 6 to theother spool 16 thereby covering the space or window between the guides6.

Between the solenoid bed 8 and the upper plate 4 there is a printingsolenoid 20. The solenoid bed is apertured to allow the solenoid core 22to reciprocate vertically. The lower end of the core 22 carries apress-printing head and two tension springs 24 connect the head to theupper plate 4, which springs urge the core 22 and the printing head in avertical, upwards direction. The head comprises a block-shaped holder26, the lower face 28 of which is recessed to accommodate a maximum ofseven side-by-side A high printing dies '30. When in position, the facesof the dies project through and below the tape guides 6.

The holder 26 is small enough to pass through the window defined by thetape guides 6 and it contains a resistance heating element, heresymbolically represented by the resistor 25, to heat the printing tapeprior to printing. The element temperature is controllable between 5 0and 300 C. and there is also a thermostat control to prevent overheatingof the tape 18.

On the reverse side of the vertical side plate 2. near the magazinespool axle 10 there is a horizontal shaft 32 which acts as a mountingfor a wind-on or indexing solenoid 34. Connected to the solenoid casingis a bifurcated lug 35 journalled on shaft 32.

Near the take-up spool shaft 112 there is an L-shaped bracket 36providing a further bearing for the take-up spool axle 12. Between thetakeup spool 16 and the side plate 2 there is a ratchet and pawlmechanism 38.

On the take-up spool axle 12 and lying between the bracket 36 and theside plate 2, is a crank 40 which is integral with the drum or inputmember of a one way spring clutch 42.

The core 44 of the wind-on solenoid 34 is urged by the spring 47 to theright in FIG. 1 and has a bifurcated lug 45 on its outer end which isconnected to the crank 40. As the solenoid core 44 moves to and fro inuse, the end of the crank 40 describes a short arcuate movement causingthe wind-on solenoid 34 to pivot slightly on the shaft 32. In theindexing direction of movement the clutch is engaged and causes indexingof shaft '12 to wind-on the tape 18, but when the solenoid 34 is deenergized the core returns under spring action to the position of FIG.1, the clutch 42 being free and the spool axle .12 being prevented fromrotating by the ratchet and pawl mechanism 38.

Referring now to the control circuit indicated in FIG. 3, the printingsolenoid is indicated by 46 and the wind-on or indexing solenoid by 48.The circuit comprises a transformer 50 of which the primary is connectedto the mains via a switch if desired and the secondary is centre tapped,rectified and smoothed to give a -22 volt line 52, a zero volt line 54and a +22 volt line 56. The switch 58 controls the operation of thesolenoids 46 and 48.

With the switch 58 in the position shown, capacitor 60 is being chargedfrom lines 52 and 54 and also the transistors T2, T4 and T6 areconducting, thus the indexing solenoid is energized and at switch-on thespool 16 is indexed to draw a small length of tape past the printinghead. i

If now the switch 58 is thrown to the other contact, as for example bytransporting upon a conveyor 27 (FIG. 1) the articles (or article) to beprinted on in positions to cause the switch to be actuated by eachpassing article, transistors T1, T3 and T commence conducting, the printsolenoid winding 46 is energized and the printing head moves down andimprints the characters of the die onto the article label or sheet orthe like under the head 28-. The winding 46 will remain energized,regardless of whether or not the switch 58 is thrown back to theposition indicated in FIG. 1 or not, for a period determined by the timeconstant of the circuit C R- the latter being variable to vary thepredetermined time. Thus, the printing head is held in position for saidtime to ensure efficient printing of the characters. In actual practice,the switch 58 will be moved to its other position momentarily and thenback to the position of FIG. 1 so that the capacitor 60 is again beingcharged during printing.

In an application of applying coding to paper wrappers, the machine isclamped by clamping brackets above a conveyor along which the paperwrappers are fed. The machine is loaded with tape as indicated in FIG. 1and the heating element switched on to heat the tape and cause a slightmelting of the printing ink so that it will adhere effectively to eachwrapper. The variable resistor R is adjusted appropriately to thedesired rate of feed and when a wrapper comes under the tape guide rail6, this causes the changeover switch 58 momentarily to initiate thesequence of operations given above.

In this event, the printer solenoid is energized and the wind-onsolenoid is de-energized, the core 22 and printing dies 30 descend andpush the stationary tape 18 into contact with the wrapper passing justbeneath the tape guides 6 to effect printing on the label.

There now follows a pre-set short delay as fixed by time constant of R Cin which the printing head is held in contact with the tape. After thepre-set interval which is usually less than a second, a change of stateas abovementioned takes place and the wind-on solenoid 114 is energizedand the print solenoid is tie-energized, being returned by spring actionand the printing head is returned by the springs 24.

The core 44 of the wind-on solenoid through clutch 42, now rotatestake-up spool 16 in an anticlockwise direction sutficiently to draw afresh unprinted area of tape from the magazine spool 14 past theprinting 'dies 30 and the circuit is again in the initial condition.

The apparatus is now ready to initiate again the changeover switchmomentarily to cause another printing. It will be appreciated that theoperation of printing is continuous, there being a complete cycle aseach wrapper passes the printing head.

We have found that the above embodiment is capable of printing speeds ofup to 5 operations/ second and with suitable printing tape will print oncellulose film, waxed papers, polythene, polypropylene, metal foils,laminates and other surfaces which are difficult to print with wet inktechniques.

In another embodiment the changeover switch 58 is a micro switch whichis moved by the cam of an auxiliary packaging machine.

What we claim is:

1. In a high speed imprinting machine employing heat transfer printingtape for printing legends on articles, the imprinting machine being ofthe type having,

(a) a printing head having means for heating the head, the printing headcarrying a printing die which can be pressed against the printing tapeby movement of the head, and

(b) indexing means for intermittently drawing the tape past the printinghead,

the improvement comprising,

a pair of spaced guide members over which the printing tape is drawn bythe indexing means, the printing head being between the guide membersand the guide members being disposed to permit the portion of the tapebetween the guide members to be contiguous to the heated printing diewhen the head is in its retracted position whereby the tape portion isheated prior to imprinting,

a first D.C. solenoid having its core carrying the printing head,

resilient means connected to the core for moving the head to itsretracted position when the first D.C. solenoid is de-energized,

a second D.C. solenoid connected to actuate the indexing mechanism todraw the used portion of the tape beyond the printing head,

a control device for energizing the second D.C. solenoid immediatelyupon de-energization of the first D'.C. solenoid by sequentiallyapplying direct current signals to the windings of the first and secondsolenoids, and

means for actuating the control device to cause the first D.C. solenoidto be energized for a time sufficient to cause a heat transferimprinting to occur.

2. In a high speed imprinting machine according to claim 1,

the improvement further including a timing circuit in the control devicefor causing the first D.C. solenoid to remain energized for apredetermined period upon each actuation of the control device.

3. In a high speed imprinting machine employing heat transfer printingtape for printing legends on articles, the imprinting machine being ofthe type having,

(a) a printing head having means for heating the head, the printing headcarrying a printing die which can be pressed against the printing tapeby movement of the head, and

(b) indexing means for intermittently drawing the tape past the printinghead,

the improvement comprising,

means for maintaining a portion of the tape adjacent to the printinghead when the head is in its retracted position to cause the tapeportion to be heated prior to imprinting,

a first D.C. solenoid having its core carrying the printing head,

means connected to the core for moving the head to its retractedposition when the first D.C. solenoid is de-energized,

a second D.C. solenoid connected to actuate the indexing mechanism todraw the used portion of the tape beyond the printing head,

a control device for energizing the second 110. solenoid immediatelyupon de-energization of the first D.C. solenoid by sequentially applyingdirect current signals to the windings of the first and secondsolenoids, and

means for actuating the control device to cause the first D.C. solenoidto be energized for a time sufficient to cause a heat transferimprinting to occur.

(References on following page) 5 References Cited 3,198,168 UNITEDSTATES PATENTS 3,331,320 2/1934 Lawson 10 1-336 X 2,714,850 10/1934Gould et a1. 101-27 5 2,801,583 8/1936 Roberts 101-9 2,672,092 8/1938Ruttiman 101-336- X 12/1942 Vahle 101-336 X 8/1944 Runton 101-336 X4/1955 Weber 101-336 10 11/ 1955 Schlessiger et a1. 10'1-336 101-27, 336

6 Weeks 101-336 X Grupe 101-27 X Young et a1 101-336 X Kistner 101-336 XLoushay 101-108 Beattie 101-336 WILLIAM B. PENN, Primary Exatrminer.

U.S. Cl. X.R.

